Complexones macrocyclic

Macrocyclic Polyamines as Biological Cation and Anion Complexones — An Application to Calculi Dissolution... 

Macrocyclic polyamines as biological cation and anion complexones — an application to calculi dissolution. E. Kimura, Top. Curr. Chem., 1985,128,113 (85). 

Complexometric titrations, 2,782 Complexones, 2,777-791 applications, 2,790 macrocyclic, 2,789 metal complexes... 

The same way was used by Yoon and Kim (2005) for the preparation of 5-(p-methoxyphenyl)thian threnium ion incorporated in a calyx[4]arene. Namely, the ratio of starting materials, methoxycal-ixarene to the thianthrene cation-radical perchorate, was 1 10. The product of such 5-anisylation of thianthrene was further transformed into a calixarene bearing an additional o-phenylene thio-macrocycle. This macrocylization is beyond the scope of this book the original paper by Yoon and Kim (2005) could be recommended for those who interested in. It is worth noting only one practical importance of the calixarene-phenylene thiomacrocycle here It selectively extracts silver(l-l-) by both calixarene and thiomacrocycle. Each molecule of this combined complexon takes up two silver cations, so that extractability achieves 165%. 

Macrocyclic complexones contain more than one aminoacetic group, which is bound over the N atom to a cyclic unit as in the case of the tetraaza macrocycles (15). Different selection effects are found in the case of these ligands (see Chapters 21.1-21.3 of this volume).67 The pAT values of the acids are much higher than those of edta they almost explain the high values of the stability constants with alkaline earth and transition metal cations. The differences in log K, between Ca2+ and Mg2+ are very high and similar to those observed for egta. For the transition metals the cyclic complexones have no advantage over the non-cyclic ones such as edta and cdta. 

A series of di-, tri- and tetra-aza cyclic and macrocyclic poly(methylenephosphonic acids) has been prepared through the Mannich-type process for use as complexones. The simplest is the piperazine-based diacid 235 and the analogous compounds based on 1,4,7-triaza-cyclononane 236 1,4,7,10-tetraazacyclododecane (237) and larger ring... 

---